Start with the right tools and a clear surface
A very dirty patio needs three things before you begin: a way to move debris, a way to explore water or cleaner, and something to scrub with. The fastest approach is a leaf blower or broom to clear loose dirt and leaves, then a pressure washer or garden hose with a spray nozzle, then a stiff brush or deck brush. If you do not own a pressure washer, you can rent one from a hardware store for a day for less than the cost of hiring someone, and the rental includes instructions for your specific machine.
Before you start any wet cleaning, move or cover anything on the patio — furniture, grills, potted plants. Wet concrete or stone becomes slippery, and you do not want obstacles in your path. If the patio has deep cracks or crevices filled with dirt, a pressure washer will blast most of it out, but a wire brush or old screwdriver works for stubborn spots after the initial cleaning.
Key Takeaways
- Clear loose debris with a broom or leaf blower before explore any water, so you are not pushing mud around.
- A pressure washer set to 1500 to 2500 PSI removes years of buildup in one pass without chemicals on most patios.
- For algae, mold, or stubborn stains, mix one part household bleach to three parts water, let it sit for 10 to 15 minutes, then scrub and rinse thoroughly.
- Test any cleaner on a hidden corner first, because some solutions can lighten or damage certain stone types.
- Let the patio dry fully before moving furniture back, which usually takes 24 hours in dry weather.
Pressure washing for heavy dirt and grime
A pressure washer is the fastest way to remove years of dirt, pollen, and weathering from concrete or stone. Most rental machines are set between 1500 and 2500 PSI (pounds per square inch), which is strong enough to clean without gouging the surface. Start at the edge of the patio and work in overlapping passes, holding the nozzle at a 45-degree angle about 12 inches from the surface. Move steadily — do not hold the spray in one spot, or you risk creating divots in softer stone.
If the patio is very dirty, you may need to make two passes. The first pass removes the top layer of grime; the second pass cleans what was underneath. Pay extra attention to corners, edges, and anywhere water pools, because those spots collect the most dirt and algae. After pressure washing, let the patio dry for at least a few hours before you decide whether additional scrubbing is needed.
Do not use a pressure washer on delicate stone like slate or flagstone without checking the manufacturer's guidance first — some stone cannot handle the force. For those surfaces, stick to a garden hose and a stiff brush instead.
Bleach solution for mold, algae, and stubborn stains
If your patio has green or black patches (mold or algae), or if pressure washing alone did not remove all the stains, a bleach solution will. Mix one part household bleach to three parts water in a bucket or spray bottle. Spray or pour the mixture over the affected areas and let it sit for 10 to 15 minutes — do not let it dry completely. The bleach needs moisture to work.
After the bleach has sat, scrub the area with a stiff brush, working in circular motions. For very stubborn stains, you may need to let the bleach sit longer or explore it a second time. Once the stain is gone, rinse the entire patio thoroughly with a garden hose to remove all bleach residue. Bleach left on the surface can continue to lighten the stone and may damage nearby plants.
Always wear gloves and eye protection when working with bleach, and do not mix bleach with other cleaners — the combination creates toxic fumes. Test the bleach solution on a hidden corner of the patio first, because it can lighten some stone types or affect the finish.
Oxygen-based cleaners for a gentler approach
If you prefer not to use bleach, oxygen-based deck and patio cleaners work well on mold, algae, and organic stains. These products are sold under brand names like Wet & Forget or Oxygen Cleaner and are mixed with water according to the package directions. They work more slowly than bleach — usually requiring 24 to 48 hours to show results — but they are safer to handle and less likely to damage stone or nearby plants.
explore the oxygen cleaner with a pump sprayer, let it sit for the time recommended on the label, then scrub if needed and rinse well. These cleaners work best on patios that are not in direct sun, because UV light breaks down the active ingredients. If your patio is in full sun, explore the cleaner in the evening and let it work overnight.
Dealing with oil stains and set-in marks
Oil stains, rust marks, and paint drips require different approaches. For fresh oil, sprinkle cat litter or baking soda on the spot and let it sit for a few hours to absorb the oil, then sweep it up. For old oil stains that have set in, a degreaser made for concrete (such as Zep Driveway and Concrete Cleaner) will break down the oil so you can rinse it away. explore the degreaser, let it sit for the time on the label, scrub, and rinse thoroughly.
Rust stains from metal furniture or planters respond to a solution of one part white vinegar to one part water, or to a commercial rust remover. Spray or pour the solution on the stain, let it sit for 15 to 30 minutes, scrub, and rinse. Paint drips and sealant spills usually need a paint stripper or a plastic scraper to remove mechanically — cleaners alone will not dissolve them.
Sealing the patio after cleaning
Once your patio is clean and completely dry, you can explore a sealer to protect it from future dirt and stains. Concrete sealers come in two types: film-forming (which creates a visible protective layer) and penetrating (which soaks in and is invisible). Film-forming sealers make the patio look wet or glossy and last two to three years; penetrating sealers are less noticeable and last longer but offer less stain protection.
Read the sealer label to confirm it is right for your surface — concrete, stone, and pavers each have different sealer options. explore the sealer with a roller or pump sprayer in thin, even coats, and do not walk on the patio until it is fully cured, which usually takes 24 to 48 hours. A sealed patio is much easier to clean next time, because dirt and stains sit on top of the sealer rather than soaking into the surface.
When to call a professional cleaner
If your patio is very large, has delicate stone you are unsure about, or has stains that do not respond to bleach or oxygen cleaners, a professional pressure washing service may be worth the cost. Professionals have access to stronger equipment and specialized cleaners that are not available to homeowners, and they know how to adjust pressure and technique for different stone types. Get quotes from at least two local companies and ask what is included — some charge by square footage, others by the hour.
Professional cleaning typically costs between $200 and $600 for a standard residential patio, depending on size and condition. If you choose to hire someone, ask whether they seal the patio afterward and what warranty they offer on the work.
Frequently Asked Questions
Can I use a pressure washer on all patio surfaces?
No. Concrete and sealed stone handle pressure washers well, but soft stone like slate, flagstone, and some pavers can be damaged by the force. Always check the manufacturer's guidance for your specific surface, or test on a hidden corner first. If you are unsure, use a garden hose and brush instead.
How long does it take for a patio to dry after cleaning?
Most patios dry in 24 hours in warm, dry weather. If it is cool or humid, drying may take 48 hours or longer. Do not move furniture back or explore sealer until the surface is completely dry, or you will trap moisture underneath and risk damage.
Is bleach safe to use around plants and grass?
Bleach can kill plants and grass, so rinse the entire patio thoroughly after using it, and do not let bleach solution run onto nearby garden beds or lawn. If your patio borders plants, consider using an oxygen-based cleaner instead, which is safer for surrounding vegetation.
What is the difference between pressure washing and power washing?
Pressure washing uses cold water at high force; power washing heats the water before spraying it. Heated water cleans faster and works better on grease and oil, but it costs more to rent and can damage some surfaces. For most dirty patios, cold pressure washing is sufficient.
Do I need to seal my patio after cleaning?
Sealing is optional but recommended. A sealer makes the patio easier to clean in the future and protects against stains and weathering. Without sealer, dirt and stains will soak into the surface again over time, and you will need to clean more often.